Scientists take the mystery out of kissing

February 24, 2009

Trust a scientist to take the romance out of life – and as we have just celebrated Valentines’ Day I saved this story until now as I didn’t want to take the fun out of it for you.

A professor of neuroscience at Lafayette College, Louisiana has examined what exactly happens during a kiss. You think she would have known from her own experience, but hey ho. In case you are wondering, kissing releases chemicals that ease stress hormones in both sexes and encourage bonding in men, though not so much in women. Personally I don’t find kissing always eases stress, but maybe I am kissing the wrong people.

If you are a sloppy kisser then you get even more stress release as it is the chemicals in saliva that change the levels of chemicals in the body. Some lucky pairs of college students got drafted for this research which involved kissing a partner for 15 minutes while listening to music. Presumably Mantovani and not Meatloaf, as it was found they experienced significant changes in their levels of the chemicals oxytocin, which affects pair bonding, and cortisol, which is associated with stress. Their blood and saliva levels of the chemicals were compared before and after the kiss which must have taken some of the romance out of it. Though as the experiment took place at the Student Health Centre that’s probably not the most atmospheric of settings.

Every subject showed a decline in cortisol when their 15 minutes was up which showed their stress levels had gone down also. In the men, oxytocin levels increased, indicating more interest in bonding, while oxytocin levels went down in women. Just to be sure they also tested couples that just held hands, and they had similar changes in body chemicals – but not to the same extent.

As proof that scientists can be just as obvious as the rest of us, I will leave you with the good professor’s final observations: “When you kiss an enormous part of your brain becomes active,” Oh really, just the brain? And to reassure you as you dust off that Valentine card, “Romantic love can last a long time if you kiss the right person.”